SU1481231A1 - Method of controlling hydrogenation process of acetylene-like compounds - Google Patents

Abstract

The invention relates to the control of the hydrogenation process and can be used in the chemical and petrochemical industry in the automation of olefin production plants. The aim of the invention is to reduce the loss of olefins. The method involves searching for the extreme value of olefin loss by varying the load ratio between reactors with a search step proportional to the calculated ratio of the olefin loss increment in the two previous search steps, and the load ratio between reactors in the previous search step. 1 il. 2 tab.

Description

Under this assumption, the olefin loss in the reactor site is calculated in block 15 as follows:

R C6 -SB

where C

., in

WITH

you

determined by the chromatograph 9 or entered into block 10 (depending on the state of the switching unit 1 1) olefin content in the reactor input streams, wt% determined by the chromatograph 12 or entered into the block 13 (depending on the state of the switching unit 14) olefin content in reactor effluent flow rates, May.7.

The optimizer 16, by correcting the setting of the controller 6, controlling the valve 7 (8), periodically changes the load ratio in roactors 1 and 2, determined in block 3 by the readings of sensors 4 and 5, by the value calculated as follows:

(Rj-i -Y

Lp

1-4 1

&P

0

five

0

Noah accuracy. The ratio of loads, ensuring the least loss of olefin. The effectiveness of the described search algorithm is due to the presence in the region of permissible values of the ratio of loads, according to experimental data, only one minimum of olefin losses.

Due to the considerable stationarity of the properties of a catalyst, the problem of load distribution between reactors can be solved with a large frequency (not once or twice a week).

Example, Initial data: allowable load ratio interval 0.8-1.4; an initial ratio of 0.75; the initial search step is 0.05; S, 0.03.

The procedure for finding the minimum loss of venison is given in Table 1.

Table 1

where unnun;

R; Rin

- change in the ratio of loads (search pag) on the i-th and (t + 1) -th search tag;

-Login losses at the i.th and (i-l) -OM search steps;

Ы is a positive component, experimentally selected within the range of 0.005-0. Thus, if as a result of the search step, the amount of olefin loss changed in the required direction, i.e. decreased, the optimizer 16 continues to change the job of the controller 6 in the same direction after a specified time interval. If the olefin losses have increased, the optimizer reverses and the assignment to controller 6 begins to change in the opposite direction.

The search procedure continues until, within the interval allowed by the process regulation, the values are found with sufficient

Thus, the desired minimum. found at the boundary of the allowable range of load ratios (n = 1,4).

PRI mme R 2. Baseline data: allowable load ratio interval 0.8-1.4; the initial ratio is 1.25; the initial search step is 0.05; oi 0.03.

The procedure for finding the minimum loss of olefin is given in table 2.

Claims (1)

Claim A method for controlling the process of hydrogenation of acetylenic compounds in parallel reactors, including the distribution of loads between reactors depending on the amount of olefin losses in the process, 15 characterized in that, in order to reduce olefin losses, they search for the extreme value of olefin losses by changing the load ratio between the reactor20 in this case, the magnitude of the current step of changing the load ratio is set in proportion to the calculated ratio of the increment of olefin loss by two previous search steps and load ratio between reactors in the previous search step.